Gear-train



C. A. PARSONS, S. S. COOK AND L. M. DOUGLAS.

GEAR TRAIN. APPLICATION FILED MAY 1.5, $918.

1,332,061. Patented Feb. 24,1920. v

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C. A. PARSONS, S. S; COOK AND L. M. DOUGLAS.

GEAR TRAIN.

APPLICATION FILED MAY 15. 1913.

1,332,061 I Patented Feb. 24,1920.

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Claude-s Algernon Ramona,

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GEAR TRAIN.

APPLICATION FILED MAY 15, 1918.

1,332,061. I Patented Feb. 24,1920.-

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Inventors: Charles Agyernonlbmm L ou is Nontz'znerflo 15%.

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C. A. PARSONS, S. S. COOK ANDL M. DOUGLAS.

- GEAR TRAIN.

APPLICATION FILED Mus. 1913.

1,332,061 Patented Feb. 24, 1920.

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UNITED STATES TENT onnIoE.

oHARLEsALG RNoN PARSONS, STANLEY SMITH oooK, AND LOUIS MORTIMER DOUGLAS, or NEWCASTLE-UPON-TYNE, ENGLAND; SAID COOK AND SAID DOUGLAS ASSIGNORS To SAID PA SONS.

GEAR-TRAHT.

1 I Specification of Letters Patent Patented Feb, 24, 1920.

Application filed May 15, 1918. Serial No. 234,787.,

To all whom it may concern: I

'Be it knownthat we, CHARLES Ancnnnon PARSONS, STANLEY SMITH Coon, and Lows MORTIMER DOUGLAS, all subjects of the King of Great Britain and Ireland, and all re siding at Heaton Works, Newcastle-upon- Tyne, in the county of Northumberland, England, have invented certain new and useful Improvements in Gear-Trains, of which the following is a specification. Y

The present invention relates to gear trains having single or multiple reduction ratios of the type in which an intermediate wheel is operated by one or more pinions,

and has for its ob'ect to arran e the ear wheels and p'inions so that the forces acting upon the intermediate pinion shaft will no tend to alter its alinement.

The invention consists in a gear train in which power is transmitted from one shaft through an intermediate shaft to a driven shaft, in so disposing the axis ofthe driving shaft or shafts relatively to the axes of the intermediate shaft and the driven shaft that the resultant reaction betweenthe first interengaging gear pair or pairs and the reaction between the second interengaging gear pair act in substantially parallel, lines.

Theinvention' further consists in a gear train comprising a primary pinion or pin.- ions driving a primary gear wheel'which is co-axial with a secondary pinion driving a secondarygear wheel, the axes of the pinions and drivenmember being so arranged that the lineof action of the force acting between the primary pinions and the primary gear wheel is substantially parallel'to the direction of the reaction between the secondary pinion and the secondary gear wheel.

The invention further consistsgi'n a gear train comprlslng a prlmary plnron drlvln'ga primary gear wheelwhich is co-axial with a secondary pinion drivinga secondary gear wheel, in which the members are so arranged that the plane passing through the axes of the primary pinion and the primary gear wheel makes with the plane 'passing'through the axes of the'intermediate pinion and the secondary gear, wheel an angle which, measured in thedirection of'rotation opposite to that of the secondary pinion, is substantially equal to the sum'of the angles of slope of the primar l eart teeth and of the secondary scribed.

' Referring .to v the accompanying draw- 1ngs:,

Figure 1 is a view of a double reduction gearing constructed according to the invention.

Fig.9 'is an enlarged view showing the slope of the teeth at the point of contact. Fig. 3 is a diagram showing the forces acting on the intermediate shaft; Fig. 4 is a view showing a modified double reduction gearing in which the'resultant forces acting on the intermediate shaft are vertical.

Fig. 5 is a diagram showing the resultant forces.

Fig. 6 is a view of the triple reduction gearing in accordance with thein'vention; while i Fig. '7 is a diagram showing the forces acting onthe intermediate shafts. I i

Fig. 8 is a diagram showing the forces acting in, a case in which two primary pinions are employed driving a single primary wheel and secondary pinion.

In carrying the invention into effect as "illustrated in Figs. l to 3 asapplied to a a primary pinion b engaging with a primary gear wheel 0 mounted on a shaft d I transmitted by means of a shaft a carrying which carries a secondary p1n1on e engagmg with a secondary gear wheel I on the driven shaft 91 r The pinions and gear wheels are preferably of the double helical type.

In a. gear pair the turning force applied from the driving to the driven member is tangential, but owing to the slope ofthe teeth Ofthe members of the pairatthe point 'of contact, see Fig. 2, there is in all cases a radial. component and consequently a non tangential reactionbetween the interengaging teeth. The direction of this reaction (in a plane. transverse to the axes) depends contact, that is'tosay, it depends upon the angle a: between'the common tangent '0 t to upon the slope'of the teeth at thepoint of secondary gear wheel f The intermediate shaft is retained in lace by the reactions of its supporting bearings in h, and as these bearings must have arunning clearance the eccentrlc poslt on which each journal takes up in its bear n is determined almost solely by the directlon of the force actingupon that journal. It will therefore be seen that if the force acting on the shaft at one end has a different radial direction from that'acting on the Other end, the shaft will not be parallel to its bearings and will consequently be out of alinement with the teeth with which it engages.

It will be seen, however, that if'the members of the train are arranged in accordance with this invention, 2'. 6. so that the angle {5 between'the common radial lines of the first gear pair and of the second gear pair respectively is equal to the sum of the angles of slope a a, of the teeth of these gear pairs; the reaction between the primary pinion 5 andpriinary gear wheel 0 and the reaction between the secondary pinion e and will. have parallel lines of action as illustrated at Fig. 3; and the forces on therespective journals of the intermediate shaft, although probably different in magnitude, will have the same radial direction and consequently there will shall be in a vertical direction. The angle' be no harmful tendency to displacement of this shaft-from its correct alinement.'- In addition to'the teeth reactions referre to above, the only other force to be considered is the weight of the intermediate shaft d, which shaft will referably be provided with abalance weig t k, Fig. 4, so that at all loads the reactions at the journals of the shaft will have substantially parallel lines of action and will consequently tend to retain the shaft in correct alinement with its bearings.

Fig. Sindicatesthe way in which the gear must be arranged in order that the reactions on, between the horizontal and the plane pass ing through the axes of the shaft (1 and the 'gearwheel f must be equal to the angle a Inthe form of theinvention shown in Figs.6 and 7, the driving shaft 0 carries pinions 6 driving gear wheels 0 and the shaft d, which also carries the pinions 6 driving gear wheelsf and a shaft m, which also carries pinions Z engaging with the gear wheels n on the driven shaft 19. Counterwei hts k g are fprovided on the intermediate afts. In this case all the forces acting onthe two intermediate shafts are vertical; as shown in r Fig. 7 I Y n the diagram, -the vertical lines 1, 2 showfresultant forces acting on the intermediate shaft d, while the, lines 3, A: show 7 ing represented by the line 7.

the forces acting on the intermediate shaft m. Inthis case it will be seen that with the directions of rotation as shown by the arrows, the resultant forces-on theintermediate shaft cl act vertically downward, and in this case the balance weight is may convenientlybe omitted. 1 7

Int e diagram shown in Fig. 8, two pri mary pinions 1, 2 operatethe. primary gear wheel 3. V The axes of the primary pinions are so disposed thatthe resultantoftheir reaction upon the primary wheel represented by the line 4: acts in' a direction parallel to i V the reaction between the, secondary pinion 5 and the secondary wheel6, this reactionbe Having now described our invention, what we claim as new and desire to, sec'urebyLettersPatent is:

1. A gear trainv comprising a driving shaft, an intermediate shaft, a driven shaft, a gear pair between the drive shaftan'd'the intermediate shaft, and a gear pair between the intermediateshaft and the driven shaft,

the axis ofithe driving shaft'being so dis,- posed relatively to the. axes of the intermediate shaft and the driven shaftthat the I resultant reaction between one interengaging gear pair and the reaction between the succeeding interengaginggear pair act in substantially parallel lines,.substantially as 7 described.

2. A gear train comprising a primary pin.-

ion, a primaryv gear Wheel, drivenby the pri mary pinion, a secondary pinion coaxial with the primary gear wheel, a secondary gear wheel driven by the secondary pinion, the axes of the pinionsand-secondary gear wheel being so arranged that the line of actionof the force acting between the primary pinion and the primary gear wheel is substantially parallel to the direction 'of'the reaction be tween the secondary pinionand secondary gear wheel, substantially as described, ,the

, primarypinion drivein whole or in part being displaced about the periphery of 'the-primary gear wheel driven by it .in relation to the plane passing through-the axes of the secondarypinion'on the shaft of-said primary gear wheel and'the secondary gear wheel driven by said secondary pinion;

3. A gear train comprising a primary pin:

ion, a primary gear wheel driven by the primarypinion, a secondaryorintermediate pinioncoaxial with the primary gear' wheel, a secondary gear wheeldriven' by the secondary pinion, ;in, which the members :are: so

' arrangedthat the plane passing through the axes of the primary pinion'and the primary gear wheel makes with the plane passing through the I axes of the intermediate pinion and the secondary gear wheel .{an angle which, measured in the direction of rotation opposite to that of the secondary pinion, is

- substantially equal to the sum of the angles of slope of the primary gear teeth and of mary ear Wheel and the secondary gear the secondary gear teeth in the plane transwheel drivenby said secondary pinion. 10 verse to the axes, substantially as described, 7 In testimony whereof we have signed our the primary pinion drive in Whole or in part names to this specification.

being displaced about the periphery of the primary gear Wheel driven by it in relation CHARLES ALGERNON PARSONS. t0 the plane passing through the axes of the STANLEY SMITH 000K.

secondary pinion on the shaft of said pri- LOUIS MORTIMER DOUGLAS. 

